In the related art, CO2 recovery devices that recover CO2 exhausted from boilers or the like of thermoelectric power plants are suggested (for example, refer to PTL 1). In the CO2 recovery devices, after an exhaust gas is introduced into a CO2 absorption tower and a CO2 absorption liquid is brought into contact with CO2 contained in the exhaust gas to absorb CO2, the CO2 absorption liquid that has absorbed CO2 is fed to a CO2 absorption liquid regeneration tower, is heated, and is decarboxylated, and a high-concentration CO2 gas is recovered therefrom. The CO2 absorption liquid is used and circulated between the CO2 absorption tower and the CO2 absorption liquid regeneration tower by supplying the CO2 absorption liquid after decarboxylation with a pump.